Two stage intermitter



Y Feb. 3; l942 v H. U. GARRETT TWO ySTAGE INTERMITTER Filed Dec. 5, 1938 lArVEhrrOR.'y

ATTORNEY.

HENRY unal. GARREIT BY W@ Feb-3, 1942- H. u. GARRETT TWO STAGE INTERMITTER Filed Dec. 5, 1938 2 Sheets-Sheet 2 E L/s INVENTOR..

HENRY (/DELL GARRETT BY W @d/@ ATTORNEY.

Patented Feb. 3, 1942 Henry Udell Garrett, Dallas, Tex., assignor to The Guiberson Corporation, Dallas, Tex., a cor-`r poration of Delaware Application December 5, 1938, Serial No. 243,975

' 11 claims. (o1. 10s- 233) In my application No. 138,926 filed April 26, 1937, which matured into Patent 2,156,429, issued May 2, 1939, I disclosed a bottom hole control choke provided with an upper and a lower packer with a by-pass leading through the. upper packer and communicating with a high pressure chamber above the upper packer. I provided a valve which would intermittently allow the high pressure gas passing down through the by-pass in the upper packer to be injected into the flow line when the head of oil in the flow line reached or exceeded a predetermined height and this high pressure gas would cause the oil to flow to the surface.

The present invention provides a two stage intermitter in which there are two pressure zones. The high pressure zone is above the upper packer with a valve controlled by-pass leading from the high pressure chamber to a low pressure chamber below the high pressure chamber. I provide one or more intermitter valves controlled by the differential in the low pressure chamber between the two packers and the pressure exerted by the head of oil so that when the oil reaches a predetermined height it will be raised into the flow line and when it has reached a predetermined height in the ow line iiow valves above the upper packer will be opened so that the high pressure gas from the high pressure chamber will be admitted into the head of oil in the flow line. I do not, therefore, use the low pressure gas to lift the oil to the surface for it is lifted to the surface in two stages, the lirst stage being the lifting of the oil by the low pressure gas into the flow line above the upper packer, the second stage being the lifting of the oil in the flow line above the upperxpacker to the surface by the high pressure gas from the high pressure chamber. For this reason I call my invention a two stage intermitter.

The advantage of the two stage -intermitter is that it is possible to lift the iiuid from the face vof high and low pressure chambers is a regulator which is used to reduce the pressure from the upper high pressure chamber to the lower low pressure chamber between the two packers. This `pressure may vary to suit requirements, but wouldy frequently vary between 60 and 100 pounds devcaused by the 10W pressure vgas or 'air which is `trapped .between two packers. Connecting the pending upon the condition of the well in which it is installed. When the small slugs'of oil'have built up a predetermined fluid level'nsid'e the long string of tubing above the upper packer and on the outside of the small tubing such vas the 1%, pipe mentioned above suicie'nt to open the flow valves, the high pressure chamber will then deliver a slug of oil perhaps three or Vfour hundred feet in length to the surface. This cycle is repeated and this would greatly increase the production of low fluid level wells.

For example, suppose a iluid level cf oil would be accumulated in a two hour period. `As the oil increases in height the pressure on the sand correspondingly increases and it might well be that it would require four hours for the oil to rise from a 1 00 level to a 200 level, and possibly six hours to increasefrom a 200' toa 300 level. by the construction shown in this application'and the process of operatingthe same, if the inter mitter near the bottom of the well is operated when the head reaches a height of 100 the pressure on the sandis relieved, which might require in` the above example two hours. The process would then bev repeated indenitely sothat the second 100' would require only two hours and. the third 100" would require two hours'. 'In order, therefore, to build up a head of 300 inthe above example six hours would be required when' my two stage intermitter was employed whereas yto build up a 300 level without my equipment would, in the above example, require twelve hours, .that is, two hours for the first 100, four hours for' the second 100' and six hours for the third 100.

It has heretofore` been` proposed to vuse a valve in the bottomof Vthe lwellfso that the Valve would be opened at the end of certain lengthslof time so as to permit the high pressure gas to move the small slug of oil to the surface. This requires expensive equipment and is not automatic in operation. Furthermore, when the clock is set to openat the end of two hourswe might or might nothave the proper head of oil. Perhaps the condition of the well might change due to the operations of oiset wells or for other reasons. With my improved construction my lower intermitter valve operates each time the proper head of oil is reached.

Another object of the inventionis to save gas or-compressedy air, so ythatonly low pressure gas isutilized to liftthe oil the short distance into have ,been (used at theintermediate stagebetween flowing and pumping a well, but with this two stage type unit it would be possible to produce more oil for less money than a well that would ordinarily be put on the pump. In other words, my device may be employed in many instances in which wells are today being pumped which would result in an enormous saving of money.

My invention may be better understood in conjunction with the attached drawings in which I have shown by way of illustration the preferred form of my invention.

Fig. 1 is an elevational View partly in cross section of the top part of the construction which In other words, Figs. 1 to inclusive are successive views, Fig.`1 being the top of the well and Fig. 5 the bottom thereof.

In the drawings the casing I extends from the bottom to the top of the well and near the top there is a gas inlet 2 through which gas such as compressed air` may be passed into the casing. It is provided with the customary valve 3. The tubing 4 extends to the top of the' well and through a cover plate 5 which seals the top 0f the casing. The tubing 4 is provided with an outlet pipe 6 in which is placed a conventional Valve 1. The tubing 4 is provided with a plurality of flow valves 8 placed at convenient distances one above the other. These ow valves extend into the high pressure chamber 9 and serve as a means to admit gas or compressed air from the high pressure chamber into the oil in the tubing as is well understood in the art. At the bottom of the tubing is a coupling I which is clearly shown in Fig. 2 and which is provided with an upwardly extending external portion II threaded to the tubing 4 and a downwardly extending threaded portion IZ threaded to the pipe I3. It is also threaded at I4 to receive a pipe I preferably about 1%" indiameter, although it should be understood that I do not limit myself to the size of this pipe or the dimensions of any other parts which I may specify. This pipe I5 is provided with a check valve I6 near its upper end as shown in Fig. l. Oil passing upwardly from the pipe I3, as heretofore described, will flow upwardly through the pipe I5 by the check valve I6 and will overilow into the oil chamber I1 between the pipe I5 and the tubing 4, the coupling I0 being the bottom of this oil chamber.

The pipe I3 as shown in Fig. 3 is received at its lower end by a coupling I8 which forms an upper retainer for the upper packer I9. A cylinprovided with external threads which receive a collar 3I and internal threads which receive a pipe 32. The collar 3I is threaded to apipe 33 which is provided with a shoulder 34 as shown in the upper part of Fig. 4. The packer 23 is provided with a metallic insert 35 which when the packer is set as shown in Fig. 4 rests against the shoulder 34 and, therefore, prevents the retainer 22 from moving nearer to the shoulder 34 than is shown in Fig. 4.

IThe packers are set in a conventional manner by rotating the pipe 33 carrying the pin 35 so Y as to remove it from its normal seat 36 and so CSI ist

drical member is provided at its upper end with a J-shaped retainer 2| to receive the lower part of the packer I9 and terminates at its lower end in a retainer 22 for the upper portion-of the lower packer 23. The coupling I8 is screw threaded to the upper end of a pipe 24, the lower end of which pipe is threaded to a coupling 25 through which extends a spring loaded safety valve 26. The coupling A25 receives at its lower end a member 21 which` is closed at its upper end 28, and which is provided -witha by-pass 29 and a radially extending hole 38. The member 28 is Vti-cally extending slot 31.

that it may pass downwardly through the ver- The springs 38 engaging the casing I are held against downward movement by friction and through the collar 39 and links 40 hold the slips 4I against downward movement. The downward movement of the cams 42 presses the slips 4I into engagement with the'casing and thereby prevents the cams 42 from moving further downwardly. The art of setting the packers is so well known and since it forms no part of the present invention, it need not be further described.

The pipe 32 as shown in Fig. 5 is provided with the conventional check valve 43. Near its lower end as shown in Fig. 5 the pipe 32 is enlarged as shown at 44 forming a chamber 45. At its lower end it is provided with a collar 46 which receives a pipe 41 which is enlarged at its lower end as shown at 48 forming a chamber 49. The enlargement 48 at its lower end receives a collar 50, which collar receives a perforated nipple 5I. The lower end of the pipe 33 is provided with a ball valve 52. The collar 46 is provided with an inwardly extending hole 53 and a collar 5D is provided with a similar hole 54. The collar 46 is also provided with la vertically extending by-pass 55 so that the chamber 45 communicates with the chamber 49. l v

The collar I8 as shown in Fig. 3 is provided withv a vertically extending by-pass 56. Thebypass 56 is provided with an Aupwardly extending shoulder 58 on which is seated a spring 59 which bears against a differential valve 6I! provided with channels 6I in its side walls. The upper end of the valve 60 normally closes a continuation 62 of theby-pass 56 which continuation communicates with a radially'eXtendingby-pass 63 which communicates with the high pressure chamber 9.

The tubing 4 and all parts carried therein are lowered in the well in the usual manner until the ball valve 52 is at or very close to the bottom of the well. The packers are then set in the conventional manner. The oil from the producing sand will unseat the ball valve 52 admitting the oil into the chamber 64 and the oil would continue to rise between the pipes 32 and 33. High pressure gas would be introduced into the casing I through the inlet pipe 2 and thereby fill the high pressure chamber 9 with high pressure gas. This high pressure gas would pass through the by- 'pass 63 and 62 shown in Fig. 3 andvwould unseat the differential valveV 60 allowing this gas to pass downwardlythrough the by-pass 56 into the space between the cylindrical member 20, and the pipe 24, which space forms achamber 51 which YI` call the low pressure chamber. It is a low pres- -sure chamber as compared withthe pressure in rthe chamber `9 for the pressure in the chamber 51 cannot exceed the pressure in the chamber 9 minus the force of the spring 59. .The low pressure gas' from the chamber 51 passes through the hole 30 in Fig. 3 into thevmember 21 andpipe 32 and into the chamber 45. It may also pass into the chamber 49 through the by-pass 55. I, therefore, have the low pressure gas in the chambers 45 and 49 and in contact with the intermitter valves 65 of well known construction. The low pressure chamber might therefore be considered as not only the chamber 51 but also the hollow part of the member 21 below the closed part thereof, the hole 30, the pipe 32 and the air chambers 45 and 49 together with the pipe 41 connecting the said air chambers. On the other hand, the oil which has risen in the pipe 33 would contact the lower end of the intermitter valves through the holes 53 and 54. 'Ihese intermitter valves may be adjusted so that when the difference between the pressure of the low pressure gas in the chambers 45 and 49 and the pressure of the oil in the chamber 64 exceeds a predetermined figure, the intermitter valves will release the low compressed air or gas into the pipe 33 and raise the oil therein through the by-pass 29, pipe 24, pipe I3 and pipe I5, causing it to flow upwardly beyond the valve IB at the upper end of the pipe I5 where this oil will overflow into the tubing 4 or into the o-il chamber I1. When the pressure of the oil is thus released the intermitter valves cease operating and the weight of the oil is, therefore, taken oi the oil producing sand for it has been raised up into the tubing and the valve I6 prevents its return. This process is repeated whereby small slugs of oil, perhaps 100' in height would be periodically removed from the bottom of the well and placed in the chamber I1. As this process continues the oil in the chamber I1 would continue to rise and the flow valves 8 may be adjusted so that whenever the head of oil in thevchamber I1 would reach a height of perhaps 300' or any other predetermined number of feet above the collar I the flow valves would be opened and would deliver the oilto the surface by the high pressure gas from the chamber 9 passing into the tubing.

In specifying that the intermitter valves 65 would be opened when the oil reached a height of 100', I mention this only by way of illustration. Obviously, these intermitter valves could be adjusted and the gas pressure in the chambers 45 and 49 so adjusted so that the intermitter valves would operate at any predetermined height of oil. The invention does not rely on any particular figures for the height of oil or the gas pressure, but the very essence of the invention is that I provide means to employ a low pressure gas to lift the oil from the sand a comparatively short distance and thereby relieve the sand from this oil pressure and I utilize high pressure gas to thereafter lift this trapped oil to the surface. It should be particularly noted that I do not allow the pressure from either the high pressure chamber or the low pressure chamber to reach the oil producing sand so that I do nothing to retard the flow of oil and at frequent intervals I relieve the pressure which is built up by a head of oil by removing the head of oil from the sand therefore greatly increasing the iiow of oil.

While the flow line might be consideredias all the pipes and connections through which the oil iiows from the lower pipe 33 up through the tubing 4, I prefer to consider that the flow line is an upper section including the tubing 4 and a lower section including the pipes I3, 24, and 33 and their connections. I do not consider that the small pipe I is a part of the fiow line in spite of the fact that the oil does flow upwardly therethrough and one reason that I do not consider it as part of the flow line is so that it might be clearly distinguished in the claims as being a pipe within the upper section of the flow line.

I realize that many changes may be made in the specific structure in this application and I, therefore, do not wish to limit myself except as I may limit myself in the appended claims.

Having now described my invention, I claim:

1. A two stage intermitter mechanism for use in wells consisting of a flow line having upper and lower sections extending from the surface of the well to a point near the bottom thereof, a capped casing, a packer on the lower section which when set defines a high pressure gas chamber between the packer and the top of the casing, means enclosing a low pressure gas chamber separated from the high pressure gas chamber, a pressure differential valve assembly leading from the high pressure 'chamber into the low pressure chamber, Ameans whereby `the gas in the low pressure chamber is periodically admitted into the fluid in the lower section so as to lift it into the upper pressure chamber, and means whereby gas in the high compression chamber is periodically admitted into the fluid in the upper section to lift it to the surface.

2. In combination, a flow line for well fluid consisting of upper and lower sections, a high pressure upper chamber and a low pressure lower chamber to contain lifting gas, intermittent valve means controlled in part by the pressure of the well fluid in the lower section to admit the gas from the lower chamber into the lower section to lift the oil in the lower section into the upper section, means to prevent the oil in the upper section from flowing downwardly into the lower section and intermittent valve means controlled in part by the pressure of the well fluid in the upper section to admit the lifting gas in the upper chamber into the upper section to lift the trapped oil in the upper section to the surface.

3. In combination, a flow line for well fluid consisting of upper and lower sections, a relatively high pressure chamber and a relatively low pressure chamber communicating with the high pressure chamber, both of said chambers containing lifting gas under pressure, valve means controlled by pressure differentials between the well fluid in the lower section and the gas in the lower pressure chamber to admit the gas from the relatively low pressure chamber into the lower section to lift the oil in the lower section into the upper section, means to prevent the oil in the upper section from flowing downwardly into the lower section, and valve means controlled by the pressure differentials between the well fluid in the upper section and the gas in the high pressure chamber to admit the lifting gas in the high pressure chamber into `the upper section to lift the trapped oil in the upper section to the surface.

4. In combination, a flow line consisting of upper and lower sections, an upper relatively high pressure gas chamber, a lower relatively low pressure gas chamber communicating with the high pressure gas chamber, intermittent Valve means to automatically admit the gas from the low pressure chamber into the lower section to lift the oil therein a comparatively short distance as compared with the total depth of the well, but sufciently far to lift the oil into the upper section, means to prevent the oil in the upper section from flowing downwardly into the lower section, and intermittent valve means to admit the lifting gas from the high pressure chamber into the upper section to lift the trapped oil in the upper section to the surface, the high pressure gas lifting the oil a greater distance than the low pressure gas.

5. In combination, a capped casing, a llow line therein for well uid consisting of an upper and a lower section, a pipe extending within the upper section and terminating below the top thereof, the lower section communicating with the said pipe and with the fluid in the bottom `of a well, means controlled in part by the head of the uid in the lower section whereby low compression gas is periodically admitted into the lower section to lift the fluid through the said pipe'into the upper section, and means controlled in part by the head of the iiuid in the upper section whereby a relatively high compressed gas is periodicallyadmitted into the upper section to raise the fluid therein to the surface of the well.

6. A two stage intermitter mechanism for use in wells consisting of a casing, a flow line consisting of upper and lower sections within said casing, sealing means between said flow line and casing to form a high pressure gas chamber therebetween, a pipe extending for a distance upwardly in the upper section, a closure between the bottom of the upper section and the pipe, means controlled in part by the head of the iluid in the lower section whereby low pressure gas is periodically admitted into the lower section to cause the liquid in the bottom of the well to be moved through the pipe and spill over into the upper section where it is trapped above the closure, and means controlled in part by the head of the fluid in the upper section and ccmmunicating with the high pressure chamber whereby a relatively high compressed gas is periodically admitted into the upper section` to cause the liquid trapped in the upper section to be moved through the upper\sectin of thek llow line to the surface of the well.

7. A two stage intermitter mechanism for use in wells consisting of a flow line having upper and lower sections extending from the top of the well to a point near the botom thereof, a low pressure intermitter controlled in part by the head of the fluid in the lower section whereby low pressure gas is periodically admitted into the lower section to lift the fluid in the lower section for a relatively short distance as compared with the total depth of the well, means to trap the uid in the upper section after being lifted by the said low pressure intermitter, and a relatively high pressure intermitter controlled in part by the head of the fluid in the upper section whereby high pressure gas is periodically admitted into the upper section to lift the fluid from its trapped position in the upper section to the surface.

8. In combination, a capped casing, a flow line having upper and lower sections, a pipe extending within the upper section, and terminating below the top of the flow line, the lower section communicating with the said pipe and with the fluid in the bottom of a well, means controlled in part by the head of the fluid in the lower section whereby low compression gas is periodically admitted into the lower section to lift the fluid through the said pipe into the upper section, means to prevent the fluid from returning from the upper section into the lower section, and means controlled in part by the head of the fluid in the upper section whereby a relatively high compressed gas is periodically admitted into the upper section to raise the fluid therein to the surface of the well.

9. In combination, a capped casing, a flow line having upper and lower sections, a pipe extending upwardly within the upper section and terminating below the top of the flow valve, the lower section communicating with the said pipe and with the fluid in the bottom of a well, pressure differential means controlled in part by the head of the fluid in the lower section whereby low compression gas is admitted into the lower section to lift the fluid through the said pipe into the upper section, and pressure differential means controlled in part by the head of the fluid in the upper section whereby a relatively high compressed gas is admitted into the upper section to raise the fiuid therein to the surface of the well.

10. In an oil well, a casing, a cap therefor, a high pressure gas inlet pipe leading into said casing, a flow line having upper and lower sections within said casing and extending from the top of the casing to a point near the bottom of the well, a packer between the flow line and the casing, the space between the cap and the packer forming a high pressure gas chamber, a low pressure chamber below the high pressure chamber and communicating therewith, a pressure valve mechanism between the chambers, means whereby said packer may be set or released, an intermittent valve mechanism communicating with the gas in the low pressure chamber and with the well fluid in the lower section and controlled by the differential of pressures of said gas and fluid whereby when a head of oil of sufficient pressure to open said Valve has been built up in the lower section the said oil will be lifted by the low pressure gas so as to move it into the upper section, means to trap the oil after thus being lifted, and means communicating with the high pressure chamber to control the flow of pressure fluid to lift the trapped oil in the upper section to the surface.

11. In an oil well, a ow line consisting of upper and lower sections, a packer thereon, a capped casing, a high pressure gas inlet pipe leading into the casing, the space between the packer and the top of the casing forming a high pressure gas chamber, a low pressure chamber communicating with the high pressure chamber, a

-pressure valve mechanism between the high pressure gas chamber and the low pressure gas chamber to prevent the pressure in the loW pressure chamber from equalling the pressure in the high pressure chamber, the bottom of said lower section being open so that the well pressure will build up a head of oil in the lower section, means controlled in part by the head of the well fluid in the lower section whereby, when the head of oil in the lower section reaches a sufficient pressure to open said means, the gas from the low pressure chamber will be admitted into said oil and move it into the upper section, and means whereby the gas from the high pressure chamber may be. admitted into the oil in the upper section to lift it to the surface.

HENRY U. GARRE'I'I. 

